Moderna chief scientist on promising new vaccine data

Moderna’s shares soared after the company said its potential vaccine to prevent Covid-19 produced a “robust” immune response in all 45 patients in its early stage human trial, according to newly released data published Tuesday evening in the peer-reviewed New England Journal of Medicine. Tal Zaks, Moderna chief medical officer, joins CNBC's Meg Tirrell and "Squawk Box" to discuss.